1. Field of the Invention
This invention relates generally to electronic game systems and more particularly to game software distributed in encrypted form for copy protection.
2. Description of the Prior Art
Portable game systems that generate player controlled objects in simulated worlds for display on an LCD screen are well known and are described in U.S. Pat. No. 6,369,827. It is also well known to store game program instructions and graphics data in digital memory cartridges that plug into such portable game systems. Even if such digital memory cartridges include a trademark and copyright notice as described in U.S. Pat. No. 5,184,830, software pirates disregard such notices. Game software in executable form is easily copied and is often sold by software pirates in counterfeit cartridges and disks and is distributed freely on the Internet. It is also known to protect programs by storing them in a digital memory in the same processor chip that executes the program instructions as described in U.S. Pat. No. 6,339,815. It is also known to include microprocessors in portable game cartridges as described in US patent applications 2002/0028710 and 2003/0050116. Crypto microprocessors that execute encrypted programs using bus encryption are also disclosed in my U.S. Pat. No. 4,278,837. It is also known to transmit video game software in encrypted form over a data transmission network as disclosed in U.S. Pat. No. 6,712,704.
Piracy of game software (program instructions and data) is similar to piracy of music software. When digitized music is read from a data storage medium or decrypted so that it can be converted to analog sounds that can be heard, the digitized music is easy for pirates to copy. But there is one major difference between music and game software. Game programs do not have to be heard or seen by their users and hence game programs do not have to be executed in easily accessible game system processors.
In the present invention, encrypted game programs can be distributed in cartridges and decrypted, stored, and executed in integrated crypto processors in game systems to generate game data, without the game programs being accessible outside of the crypto processors.